Crown for combined winding and setting stems of timepieces



May 16, 1950 G. HENRY CROWN FOR COMBINED WINDING AND SETTING STEMS OFTIMEPIECES Filed Feb. 28. 1946 lfl VE-Nnie GEOQGES Han e) Patented May16, r 1950 CROWN FOR COMBINED WINDING AND SETTING STEMS OF TIMEPIECESGeorges Henry, Geneva, Switzerland Application February 28, 1946, SerialNo. 650,784

In Switzerland April 25, 1945 4 Claims.

'There exist numerous classes of spring actuated time pieces, servingeither for time indicating, time recording or for automaticallycontrolling functions which are to take place at predetermined times.

Most of said time pieces comprise a housing or case, and a mechanismoften called the movement housed in said case. This movement includes amain spring actuating time indicating means (hands or figure carryingmembers or other moving indexes or other actuated organs for controllingsaid function), motion transmitting means between said main spring andsaid indicating means, a stem connecting at will either with said mainspring or said indicating means within said case and reaching throughthe wall of said case to the exterior. This stem enables both thewinding of said main spring and the setting of said time indicatingmeans to be performed from the outside of said case, and a crown at theend of said stem serves for the manual control of said stem, the outerboundary surface called later the peripheral surface of said crowngiving the proper grip for said manual control. Of all classes of springactuated time pieces, the most important one by its large number ofpieces in use is certainly the watch. For this practical reason most ofthe present description refers to the watch but this should not be takenas a limitation in the application of the present invention.

In most watches known, it is possible to mount the combined winding andsetting stem only after the movement has been placed in the case. Thestem, already equipped with its crown, is then introduced from theoutside through an opening of the case, usually provided with a tubethere, and held in place by the action of a screw located on themovement in the case.

This feature did not show serious inconveniences with the older types ofwatches although it was necessary to open the case and expose themovement to dust for themere replacement of a defective or worn-outcrown for instance; but with the modern types of so called waterproofwatches, the question is quite different.

The watch manufacturer was compelled to take great pains in the designand execution of the bottom of the case in order to insurewatertightness of the joint with the case and at the same time find amechanical connection between these two elements which would discouragethe amateur from removing the bottom of his watch for the sake ofcuriosity. Indeed, when this happens to a watch, its waterproofqualities are almost certainly lost. This is one reason for the peculiarpolygonal or notched bottoms known and requiring a very special key forthe opening and tightening of the waterproof bottoms.

Considering on the other hand the commercial importance of externalappearance of the watch case and in view of the continuously varyingtaste of the buyer, it would be very advantageous for the merchant oreven for the manufacturer to be able to take a complete movement, allready, tested, regulated and mounted in its watertight case, and dressit with an outer shell at the choice of the customer,

From the above, the serious advantages may be appreciated which would beafforded by the use of a crown mountable from the outside and whichwould not necessitate the opening of the case for this work.

Various solutions of this problem are known. Some, consisting in a sortof elastic chuck connecting a one-piece crown with the stem, presentdifliculties for the water-proof watch owing to the clearance requiredfor the proper operation of this chuck and the resulting unsecurefunctioning or loosening of the crown.

Others consist in a crown held from the outside by means of a screw or ablind nut tightened axialy on the stem; unfortunately, all forms knownof this type have the great disadvantage of modifying the externalappearance of the crown and, which is worse, of leaving the unmistakableindices of the manner in which the crown is fastened (slot, holes ornotches). serious danger for the waterproof watch in which a watertightpacking is usually provided between stem and case. Indeed when such acrown has been taken apart and reassembled once by the amateur, chancesare that it will never be tigh again.

The invention has for its object a crown of usual external shape for awinding and setting stem to be used in connection with any time piecewhose movement is enclosed in a case. It may be mounted from theexterior without necessitating the opening of said case and is free fromthe inconveniences set forth above. This crown is made of two distinctparts, coaxially superposable, one of these parts being provided withorgans for its coupling in rotation with the stem, while This is acontribute in a substantially equal manner to the formation of the totalperipherical surface of the crown so constituted. Once assembled, saidcrown shows no evident trace of the manner in which it is held in place.

Another character of the invention is to allow for the use of awatertight packing or seal of usual design between the case and thecrownpart which is closest to the case, as well as for an intermediatepacking between both crownparts.

Further, with watches which are not of the waterproof type, the packingmay be either left out entirely or replaced by an elastic member.

The elasticity of said packing or said elastic member, added to the ownelasticity of one at least of the two crown-parts facilitates duringassembling the small flutes directed substantially parallelly with theaxis of said stem and with which both parts may be provided, to bebrOught to lineup exactly.

The accompanying drawing shows by way of examples two forms ofembodiment of the invention.

Fig. 1 is a perspective view of an assembled crown;

Fig. 2 is an axial section of a first form of embodiment;

Fig. 3 is an axial section of a second form of embodiment.

With reference to the drawing, a case i is provided with a tube 2tranversed by a combined winding and setting stem 3 equipped with aportionwith square cross-section t and a threaded portion 5. A crown 6has its peripherical portion divided across the hight by a planeperpendicular tothe axis of the stem in two substantially equal parts orhalves 6a and b contributing in substantially'equal manner to theformation of the peripherical surface 60 of the resulting crown.

The difference in diameter between tube 2 and the-portion of the stementering said tube is sufficient to-allow for the easy introduction ofthe stem'into the tube when placing the whole mechanism equipped withthe stem into the case. The portion 61) of the crown terminates in acylindrical sleeve 1 whose outer diameter leaves the clearance usuallygiven between an ordinary stem andthe case tube. The end of said sleeveis providedwith a square hole to match with the portion 4'with squarecross-section of the stem thus obtaining a coupling in rotation betweenstem and'crown part 6b, closest to the case. It is quite obvious thatthis arrangement, although most common in watches, may be replaced byany equivalentzmeans coupling said two parts in rotation. Crown-half 6bis equipped with a so called watertight packing or seal of known design8. Crown-half 6a terminates in a cylindrical portion provided with athreaded hole for screwing said halfon said threaded end 5 of said stem.Between both crown-halves 6a and 6b, a recess is provided for thehousing of an intermediate watertight packing ID for efficiently sealingthe clearance space left between said two crownhalves. When the new typeof crown is to be used for an ordinary watch, i. e. not of thewatertight type, this intermediate seal may be simply left out orreplaced by an elastic element, a spring washer for instance asindicated by I9a in Fig. 3.

As already referred to previously, the complete movement, equipped withits winding and setting stem, is placed as a whole in the case.

The movement is held inclined with respect tothe case and the stem endintroduced in the inner tube opening. By gradually establishingparallelism between movement and case the stem may be fully engaged inthe case tube and the movement reaches its final position in the casewhere it may be fastened in any usual manner.

Crown-half 6b is slipped over the stem and in case tube 2, engaged oversaid stem square 4 and held in a clamping tool which thus maintains thestem against rotation. Crown-half 6a is then screwed tightly on the stemby means of a wrench. In the case where the crown-halves are providedwith the usual knurling made of small grooves or flutes substantiallyparallel to the axis of the stem, the surface of the flutes serve for abetter grip of both said clamping tool and wrench whose shape shouldthen be made to match said flutes.

The upper crown-half is hollowed-out and a relatively thin and flexiblemembrane thus formed affords sufficient elasticity to allow for theexact lining up of said flutes provided in both crown-halves whentightening upper crown-half 6a. Lower crown-half So being alsohollowedout to a certain extent gives additional elasticity as well asthe intermediate packing itself or in the ordinary watch the elasticmember already mentioned.

Owing to the fact that both crown-parts contribute in a substantiallyequal manner to the formation of the total peripherical surface of thefinished crown, it is possible to give the latter the usual shape andappearance, the division in two halves leaving but an almost invisibleline across the knurled or fluted portion and giving at any rate noevident indication as to how the crown is fastened on the stem.

The combination described seems to be the most obvious one, but it isevident that both crown-halves may be inverted in their relativefunctions. Instead of a drilled-out part with a square hole and a partwith a blind threaded hole, the combination of a drilled-out part and apart with a blind square hole may be used.

Fig. 53 shows a slightly different form of embodiment of the inventionallowin each crownhalf to perform individually and independently fromthe other the mechanical functions of a usual one-piece crown. In thisdesign, the extremity lb of sleeve 1 of crown-half 6b is thinned out andprovided with a slight internal bead 'lc engaging with a correspondinggroove lb provided on the square of the stem. The elastic chuck thusformed permits of a checking of the proper functioning of the windingand setting steam without requiring the other crownhalf tobe fastened onthe stem. The fact that such an elastic connection may be disengagedeasily by a simple pull on the crown-half is no objection here as is thecase with known designs of similar type used with one-piece crowns knownand mentioned in the introductory part of the present descriptionbecause for ordinary use, the lower crown-half is firmly held in placeby the upper crown-half.

It may be seen readily that when leaving out the lower crown-half, theupper-half may be screwed tightly on the stern until the end face of itscylindrical central portion comes to rest against the square shoulder ofthe stem and may thus allow for the checking of the proper functionin ofthe stem as is the case with the lower crown-half alone.

It is quite obvious that without departing from the spirit and scope ofthe present invention, a split crown such as described may be used forcontrolling from the exterior the winding and setting stem of any timemechanism enclosed in a case, with particular reference to devices whichshall be protected by watertight or fiuidtight cases or more generallystated in tight housings.

I claim:

1. In a time piece, the combination, comprising, a case, a stem mountedin said case for axial displacement and rotation, said stem including apart extending from one end and having a threaded and a polygonalportion, a first crown part including threaded means coacting with saidthreaded stem part, a second crown part mating with said polygonal stempart for rotation therewith, flutes formed on the peripheral surfaces ofboth crown parts, a recess formed in one of said crown parts and openingtoward the other part, and elastic sealing means in said recess forholding said crown parts in a predetermined position of alignment of theflutes in both crown parts.

2. The combination according to claim 1 and also comprising anotherrecess in one of the crown parts nearest said case, and sealing meanshoused in said other recess.

3. In a time piece, the combination, comprising a case, a stem mountedin said case for axial displacement and rotation, said stem including apart extending from one end and having a threaded part and a polygonalpart, a first crown part including threaded means coacting with saidthreaded steam part, flutes formed on the peripheral surfaces of bothcrown parts, a second crown part mating with said polygonal stem partfor rotation therewith, a recess in one of said crown parts partlyoccupied by the other of said crown parts, and elastic sealing means insaid recess for holding said crown parts in a predetermined position ofalignment of the flutes in both crown parts.

4. The combination according to claim 3 and also comprising anotherrecess in the other of said crown parts and extending into said firstrecess, and sealing means in said other recess.

GEORGES HENRY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,270,384 Simon Jan. 20, 1942FOREIGN PATENTS Number Country Date 2,203 Great Britain Jan. 26, 188479,360 Switzerland Apr. 1, 1919 182,768 Switzerland June 2, 1936 208,581Switzerland May 16, 1940

